Asymmetric Michael addition/intramolecular cyclization catalyzed by bifunctional tertiary amine-squaramides: Construction of chiral 2-amino-4H-chromene-3-carbonitrile derivatives

The efficient asymmetric Michael addition/intramolecular cyclization of malononitrile with dienones catalyzed by a chiral bifunctional tertiary amine-squaramide catalyst for the synthesis of chiral 2-amino-4H-chromene-3-carbonitrile derivatives was developed. The corresponding products were obtained in good to excellent yields (up to 99%) with excellent enantioselectivities (up to 98% ee) for most of the bisarylidenecyclopentanones.